I don't think anyone should be discouraged from asking questions. I love to ask questions. Is there anything wrong with it? (see, just asked one ) I agree it can get a little tiresome, but the solution to it is not to answer.

I understand you find a concept and want to question where others do or don't do it.

For one thing, many of us would not answer such a question if someone came into our schools 'demanding' an answer. Most systems have an internal order to instruction, waiting till the students abilities rise to the level of the technique.

The movement you're qestioning might have severe reprecussions is used, but then there are any number of techniques that can do the same, hurt someone badly.

Off hand I can think of a number of karate systems that use that technique openly in their instruction, at the appropriate level, and I'm quite sure there are others that do so more privately. Or you can go outside of karate into a system like the Bando Boar that uses the same technique.

Let's suppose that I might do so in the Isshinryu I teach, on the assumption that the Isshinryu hand stiking formation lends itself to such a use, that instruction would not happen till well after the student is in their black belt studies, and only as a minor variation usage of the vertical striking fist.

There are various reasons why it is not taught earlier, but the most appropriate one is in our current local there is absolutely no need to address it differently. Other times and places I might reconsider that answer.

The technique is neither more or less effective than many other techniques.

My answer of course is only theoretical, especially as I'm not looking for students, nor choosing to give away the manner in which we instruct.

Truthfully, if you want real answers, you have to wait till you can begin serious study, and then find them out in time.

Almost everything taught in MARTIAL ARTS can kill someone. That is why they are MARTIAL ARTS!!! If applications are not obvious to a white belt, they become more numerous and clear as you move through the ranks. If a person wanted to just learn the moves for health applications, they'd study cardio-kickboxing.